In conventional SS7 networks, message screening can occur at signal transfer points (STPs) in order for the service provider that owns the STP and the associated network to control access to the network. For example, a service provider may desire to only pass SS7 signaling messages that are from another service provider with which the first service provider has an agreement. Another example in which screening may be desirable is when a service provider wishes to block certain types of traffic, such as SPAM SMS (Short Message Service) messages, from entering the network. Yet another example in which it may be desirable to screen incoming SS7 messages is when the messages request information regarding the service provider's subscribers. In this example, it may be desirable to block such queries, charge a fee for the queries, or only allow queries of a certain type or from an authorized destination.
Screening of incoming SS7 messages at an STP has traditionally been performed at the message transfer part (MTP) or the signaling connection control part (SCCP) level. While screening at the MTP or SCCP levels may be effective for controlling traffic to or from a particular node, such screening does not effectively allow screening based on upper layer protocols in messages, such as MAP protocols.
MAP messages are SS7 messages that reside on top of the transaction capabilities application part (TCAP) and SCCP protocol layers. MAP messages carry services used by mobile telephone subscribers, such as anytime interrogation (ATI) service and short message service (SMS). Anytime interrogation service is a service in which queries can be sent from SS7 service control points (SCPs) to home location registers (HLRs) to determine information regarding mobile subscribers. It may be desirable for the owner of the HLR to identify ATI messages and determine whether the requester should be given access to the information. Similarly, it may be desirable to identify and police SMS messages so that subscribers and/or service providers can be charged for SMS message delivery.
Identifying and policing higher level protocol messages, such as MAP messages, is difficult, if not impossible using conventional gateway and SCCP screening alone because these functions work only on lower layer information. Accordingly, there exists a long-felt need for novel methods and systems for mobile application part (MAP) message screening.